Injection molding systems have been developed having flow control mechanisms that move at high speed over relatively short periods of time to control the rate of flow of fluid material that is being injected to a mold cavity. The range of distance of movement or travel of the flow control mechanisms is also relatively small. Computer/algorithm electronic controls have been developed to effect such movements on the basis of a variable input that corresponds to a sensed condition of the fluid material being injected or another sensed property, state or condition of a component of the apparatus or the energy, pressure or power used to operate an operating mechanism associated with the apparatus that is used to control the flow velocity of the fluid material.
The accuracy and precision of such algorithmically controlled movement depends on the accuracy/precision of the sensed condition as a measure of flow velocity at any given point in time or at any given location within the fluid flow stream where the fluid or machine property is being sensed by a sensor.